Just got a 73 Plymouth Valiant 4dr

Hi!just Bought A 73 Dart Swinger 318 Auto.not Sure On This But With The 318 I,m Thinking 8 1/4,just Cause Of The V8.i,m Also Robbing The Front U.control Arms And Disc,s To Convert My 66dart To Bbp Disc Brakes Also Gonna Swap 7 1/4 To 81/4 4.10 S.g.so I Will Now Have A Spare 318 And Tranny.66dart Has Slant With 4 Barrel And Headders,dual Exhaust.i,ll Be Able To Put Bbp Ralleyes 14 Front 15 Rear.hope Some Of My Yammering Helps